Brake for vehicles



March 2 1926. 1,575,191

L. COATALEN BRAKE FOR VEHICLES Filed Dec. 13, 1923 INVENTofZ:

I LOUIS COATALEN 1aj-g M Patented Mar; 2, 1926.

UNITED STATES 1,575,191 PATENT OFFICE. I

LOUIS coammnv, or wonvnnnmrron, EN LAND, AssIeNoa TO snmmau moron cnaoomrnny, Lmrrnn, or woLvEnHAmrroN, ENGLAND, A BRITISH COMPANY.

BRAKE FOB VEHICLES.

Application filed December 13,4928. Serial No. GSOAOLHEISSU To all whomit may cone-em: I

Be it known that I, UIS CoA'i AIQEN, a subject of'the King of. Eng and,residing at Wolverhampton, in the county of Stafford, England, haveinvented certain new and useful Improvements in Brakes for Vehicles, ofwhich the following is a specificatio This invention relates to servo-oerated brakes for use on vehicles, of the rind in which two brakemechanisms are contained in a single drum, one being positively appliedtothe drum and being connected to the second so that movement of thefirst 5 operates, servo fashion, to apply the second mechanism. Hithertofor this purpose a construction, has been suggested in which the drum;was ,enga ed by two expanding bands of which the rst, or servo band, was

a narrow one in the centre of the drum,

and the end of this was connected to the end of a wide channel shapedmain band the other end of which was pivoted to a fixed point.

The object of the present invention is to provide a construction ofservo .brake mechanism of this kind enabling only two shoes or blocks tobe used, one operating, servofashion, to apply the second shoe or block.The figure is' a side elevation showing .one embodiment of the inventionAccording to this invention, the drum contains two segmental shoes, oneon eachside of the axis of the drum and located in the same radialplane, of which the first or main shoe is pivoted to a fixed point, andthe second or servoshoe is free to move around the axis'of thefdrum andis connected with the free end of-the first shoe, with means acting uponthe servo shoe to .ap 1y it to the drum.

referably the operative connection between the servo shoe and the mainshoe is such that the latter can also readily be applied directly bycontrol mechanism which 1s independent of that employed for applyingtheservo shoe. Thus it is possible to use the main brake in the ordinarymanner to hold against motion in either direction, and it can also beused as an emergency brake in the ordinar manner.

In one method 0 carrying out the invention for an" expandingbrake, theshoe A formingthe mambrake is suspended or supported, as by ivoting inthe usual manner from one en A and at the other end is acted upon by acam B which is pivoted to a fixed part, such as the anchor plate C, andis rovided with a short arm D or lever to e ect its angular movements.

The servo brake is a single. shoe E arranged inside the drum F oppositeto the main brake shoe A and is at one end suported by a radius rod G,which is anguarly movable about the axis 1* ofthe brake drum, thusallowing circumferential freedom of movement for the servo brake shoe.The end of the servo brake shoe thus supported, is, by the agency 'of alink H, operatively connected to the arm; D of the cam actin upon themain brake, the disposition 0 the parts being such that when the servobrake shoe E 'is applied to the drum F it's circumferential movement-dueto the movement of the drum acts to apply vthe main brake A through theparts H and D.

The servobrake shoe E is acted upon by a cam J at the end remote fromits suspension means so as to bring it into engagement with the brakedrum, and this cam as'usual r so that their arrangement in this respectbroadly resembles that pending brake.

An important feature of the invention is the PIOVlSlOIl of means foroperating the main brake shoe A quite independently of the servo brake.To efiect this in a simple manner the cam B which acts directly upon theshoe A is operatively connect d to the side or hand brake lever as bythe arm L and rod M through some form of joint which ma embody aflexible or sliding connection a apted to permit of the movement of thecam underthe operation of the servo brake quite independently of theadditional mechanism provided to operate-it independentl of the servobrake.

O viousl the link H is not nectssary as the end 0 the shoe. E -'mayengage the arm D; It will be seen from the foregoing that the servo andthe main brake are effectively of an ordinary excombined to ether in asimple and direct,

cupied, and virtually no, parts other than would be required for anordinary expanding .or contracting brake.

\Vhat I claim as my invention and desire nectionbetween. the'fother endof said main shoe and the adjacent end of said servo shoe, including alever anda cam operated thereby, said cam engagi said main shoe.

2. In a brake for a vehlcle, the combinas tion of a drum, a mainsegmental shoe inside said drum, a servo segmental shoe inside saiddrum'and on the, opposite side of the axis thereof from said main shoe,a fixed pivot for one end of said main shoe, an operative connectionbetween theotherend of said inain shoe and the'adjacent end of saidservo shoe, including a lever anda cam oper- .-ated thereby, said. camengaging said main -shoe,and means for directly applying the main shoeto the drum in addition to its application through the connectionwiththe servo shoe, substantially as set forth.

3. In a brake for a vehicle, the combination of a drum, a main segmentalshoe inside said drum, a servo segmental shoe inside said drum and onthe opposite side ofithe axis thereof from said main shoe, 9. fixedpivot for one and of said main shoe, an operativqconr: :,:tion betweenthe other end of said main shoe and the adjacent end of said servo shoe,including a lever and a cam operated thereby, said cam engaging saidmain shoe, and a link from the leverto the servo shoe, substantially asset forth.

4. In a brake for a vehicle, the combination of a drum, a main segmentalshoe inside said drum, aservosegmental shoe also inside said drum and onthe opposite side of the axis of said drum, a fixed pivot in one end ofsaid main shoe, an operative connection between the other end of said"main shoe and the adjacent end of said servo shoe, means for applyingthe servo shoe to the interior of said drum, said operative connectionbetween the shoes comprising ,a pivoted cam engaging the main shoe, alever on the cam, and a link from the lever'to the servo Shoe, and meansfor actuating the cam directly as Well as from the servo shoe,substantially as set forth. a

5. In abrake for a vehicle, the combination of a drum, a main segmentalshoe inside said drum, a servo segmental'shoe also inside said drum andon the opposite side of the axis of said drum, a fixed pivot in one endof said main shoe, an operative connection between the other end of saidmain shoe and the adjacent end ofsaid servo shoe, means for applying theservo shoe to the interior of said drum, means for directly applying themain shoe to the drum in addition to its. application through theconnection with the servo shoe, a radius rod G free to swing about theaxis of the drum, said servo shoe'being pivoted to said radius rod,

substantially as set forth.

In testimony whereof I have signed my name to this specification.

LOUIS COATALEN.

